Date of Award

Winter 2019

Project Type

Dissertation

Program or Major

Chemistry

Degree Name

Doctor of Philosophy

First Advisor

Roy P Planalp

Second Advisor

W. Rudolf Seitz

Third Advisor

John Tsavalas

Abstract

The responsive material poly-N-isopropylacrylamide phase-transitions from hydrophilic to hydrophobic conformations above 32 °C in aqueous media. Researchers have successfully tied that responsive behavior to other dissolved species such as pH, metal concentrations, and even glucose concentration. From our interests in developing sensor technologies we ascertained that direct interactions between metal ion and polymer had received little to no attention. Our investigations into this literature gap discovered that dissolved metal ion only slightly shifts the lower critical solution temperature. However, metal ion greatly increases the size of polymer aggregates, and is found to bind directly to the polymer. We present a metal crosslinking scheme that fully rationalizes our observations. Due to difficulties in examining our system, we also present a second order scattering method of original design for determining particle size during dynamic aggregation processes.

Global consumption creates a market demand for cheaper more available materials such as polyacrylates. For decades chemists have sought a catalytic route for producing the acrylic acid monomer from C2H4 and CO2 precursors. Very recently that goal was realized, but the system requires considerable improvements before becoming appropriate for large scale production. We investigated the cycle’s most troublesome catalytic intermediate, a nickelalactone chelated by bidentate phosphine ligands. Using the Dubois motif, we synthesized a family of PNP nickelalactones and the corresponding carbonyl complexes. These compounds we thoroughly characterized by NMR spectroscopy. Based on thermal stabilities the cyclohexyl phosphine derivatives were better suited for catalysis than their phenyl analogues.

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